Apparatus for compensating for the effects of non-circularity of unwinding rolls



United States Patent 1111 3,54

[72] Inventor Horst Moehle [56] References Cited e Germny UNITED STATESPATENTS 3 5 1 1968 680,706 8/1901 Edmunds 242/7543 [22] P1 e d Nune",1970 1,103,144 7/1914 Hunting... 242/7543 f g g Wake AG 1,882,57810/1932 l-lardiman. 242/753 8 D g u f, G 2,755,032 7/1956 Justus242/7543 P a 3,013,740 12/1961 Macomber 242/753 [321 3,288,385 11/1966Markakisetal. 242/57x 3,201,9 5 8/1965 Williams 242/7543 PrimaryExaminer-Nathan L. Mintz Attorney- Burgess, Dinklage and SprungABSTRACT: An apparatus for compensating for the adverse effectsoccasioned by noncircularity of unwinding or delivery rolls in paperprocessing machinery such as roll cutting or slitting machines,rewinding machines and similar machines [54] APPARATUS FOR COMPENSATINGFOR THE which operate in dependency upon a delivery roll and in EFFECTSOF NON'CIRCULARITY 0F which a measuring or sensing means influenced bythe tensile UNWINDING ROLLS stress of a web fed from a delivery orunwinding roll controls a 3claims4nnwing Figs brake operably associatedwith the shaft or axis of such [52] U.S. Cl. 242/7543 delivery rollcomprising a low weight guide means interposed [51] Int. Cl. Bh 77/00 inthe path of web travel between the unwinding or delivery [50] Field ofSearch 242/ .43, roll and the measuring or sensing means and acting uponsuch 75.42, 75.44, 75.3 web in pressure yielding fashion.

I 10 {is 5 I l 1 11.1 5 9 8 Patented Nov. 17, 1910 3,540,671

Sheet 1 or 2 Patel fled Nov. 17, 1970 Sheet 2 of 2 1 APPARATUS FORCOMPENSATING FOR THE EFFECTS OF NON-CIRCULARITY OF UNWINDING ROLLS t Thepresent invention relates broadly to the art of winding and reeling.More particularly, this invention relates to the winding and reeling ofpaper and the like material.

Specifically this invention relates to an apparatus for com- In theprocessing ofcontinuous webs of. paper or the like, as

for example in longitudinal cutting or slitting operations,

transverse cutting, rewinding, etc. it is of particular importancc thatthe paper web which is being unwound from the delivery roll be fed tothe processing location under uniform tensile stress. ln order toaccomplish this purpose, a web tension regulator compensating for thepaper webs tensile stress is generally embodied in the machinesubsequent to the unwinding apparatus. The arrangement thereof is suchthat the paper web is conducted or passes over a pivotally mountedroller which swings out according to. each sensing of tensile stress,thereby imparting impulses to a brake which acts upon the unwinding axisor shaft. The primary function of this type of web tension regulator isto adjustthetensile stress of the paper web to a preselected desiredvalue by means of appropriately acting upon the .brake as said tensilestress increases due to the decreasing diameter of theunwinding'roll.

Quite frequently, however, there occur substantial fluctuations in thepaper web on account of noncircular unwinding rolls. The frequency ofsuch paper web fluctuations can become so great as to render impossibleany compensation therefor through the web tension regulator for thereason that the entire regulating system is too inert. As a resultthereof, the web's tensile stress is not being regulated at all, or ifit is, then such regulation occurs too late. The reason for thesesubstantial paper web fluctuations being caused by noncircular unwindingrolls is that as the web unwinds, there are being unwound during thatprocess periodically fluctuating paper lengths per time unit,-thusstretching the web rhythmically analogous to said changes in length. Theextent of stretch can thereby'become so great as to stop just short ofthe breaking point. However, if in a web stretched thus enormously thereappear further tensile stresses, for example in a printing 1 machine,the result may be the much-feared web break,- thereby possiblydamagingthe printing cylinder. Although no damage of the deflector rollsor the like need be feared, if the breakfoccurs already within therewinding machine, considerable disruptions in the entire operationalsequence are caused as a result thereof.

Thus, the primary object of this inventionis to produce an apparatuswhich overcomes and removes the aforesaid drawbacks and difficulties andeliminates the paper stress fluctuations occasioned by noncircularunwinding rolls.

It is a particular object of the invention to provide an apparatusincluding a mass-deficient, that is low or light weight,

and pressure-yielding guide member mounted between the un-. winder rolland the measuring or sensing member; which is acted upon by the web'sstress, said guide member operating counter to the motion of the paperweb.

it is a further object to provide such mass deficient guide membershaped in the form of aspring-suspended arm to which is attached apressure guide extending across the entire width of the web.

As a still more specific object and for adjusting the contact pressureof the pressure guide against the paper web, the spring-suspended arm ismounted for lateral as well as vertical adjustment and/or the effectivelever length of the arm is adjustable. Furthermore, the arrangement canbe such as to associate certain implements with the guide member whichestablish a friction-reducing air cushion between the paper web and theguide member.

Further-and more specific objects and advantages will be apparent fromthe following description taken in connection ments of the inventiveapparatus.

As indicated in FIG. 1, a paper web 1 is pulled off from an unwindingroll 2and conducted to a rewinding roll 10 via a guide member comprisinga pressure guide 3 having an areaate web-contracting surface and an arm4, a measuring roll 5 is, a longitudinal cutting or slitting mechanism6,7 and transportation rollers '8 and 9. The measuring or sensing roller 5carried by a lever arrangement 5"that is swingably mounted about axis 5"and by responding to the respective tensile stress of the web acts uponbrake 11 through means which are well known to the art, said brake inturn acting upon the axis, or shaft of unwinding roll 2. inasmuch as innoncircular unwinding rolls the frequency of theweb's-stressfluctuations is .so'great as to prevent the measuring roller5 from swinging out, or if it does swing out, then at too late a stagebecause of its'own inertia,-the invention teaches mounting of a guidemember comprising pressure guide3 and arm 4 in the path of paper feedbetween measuring roller 5 and unwinding roll 2.

The paper web 1 is thereby acted upon in pressure-yielding I fashionby-pressure guide 3.

By means of using suitable materials, dimensions and ar rangement forthe guide means 3, 4, it can follow without effort and almostinertialess the highly frequent web stress fluctuations, so that thelatter can be equalized thereby.

As shown particularly in FIG. 2, arm 4 of the guide member is mounted inaslot in an axis or shaft 12 so that it is adjustable and securablyheld, so that the pressure being exerted upon web I can be adjusted asdesired by changing the effective length of lever arm'4. Shaft 12 isrotatably and securably mounted in a bearing 13 which is attached tomachine frame made possible as depicted in dotted line in FIG. 2, saidadjustments being required in order to vary the pressure acting upon web1.

The embodiments depicted in FIGS 3 and 4 show as a further developmentof the invention the guide member 3, 4 having associated therewithimplements 15,16 for producing an air pressure cushion-between pressureguide 3 and web 1. In the embodiment depicted in FIG. 3 the arrangementis effective to introduce compressed air between the paper webl andpressure guide 3 through several air. jets l7- distributed across the,width of the web for establishing an air cushion. The air'jets l7 areconnected with an air compressor not otherwise shown in the drawingsthrough conduits 18.

FIG; 4 illustrates another embodiment for producing the air cushionbetween paper web 1 and pressure guide 3. in this embodiment, pressureguide 3 is provided with a notch 19 extending across the width of theweb. Compressed air conduits 20 made of rubber-elastic materialcommunicate with this notch or groove. These conduits 20. have loops 21therein for relievingpressure guide 3, and are likewise connected withan air compressor or compressed air source not shown in the drawings. 1

lclaim:

1. Apparatus for compensating for the effects of noncircularity ofunwinding rolls in roll cutting machines, rewinding rolls or othermachines of the type which operate in depen-.

dency upon a delivery roll, which machines include an unwinding axis forsuch an unwinding roll, measuring means influenced by the webs tensilestress, a brake operably associated with said unwinding axis, saidmeasuring means being operably coupled to said brake for controlling thesame in accordance with tensile stress variations, a light weight guidemeans interposed in the path of web travel between said unwinding rolland said guide, means comprising a resilient arm and means defining ashaped stationary guide surface engaged by said web from above,extending across the entire width of said web, and carried by saidresilient arm and means for adjusting the position of said arm includingmeans for swingably adjusting said arm and guide surface relative tosaid path of web travel about an axis parallel to said unwinding axisand

